Dual layer line engaging device

ABSTRACT

A LINE GRIPPING DEVICE HAVING AN UNDERLYING SET OF PREFORMED HELICAL WIRES APPLIED OVER THE LINE, AND A GRIPPING MEMBER HAVING HELICALLY FORMED WIRES GRIPPINGLY ENGAGING THIS UNDERLYING SET OF WIRES. THE GRIPPING MEMBER IS PROVIDED WITH MEANS FOR ENGAGING AN ANCHORING DEVICE.

Nov. 9, 1971 J. c. LITTLE 3,613,308

DUAL LAYER LINE ENGAGING DEVICE Original F1led July 29, 1968 2Sheets-Sheet z INVENTR. Jess C. Liflle l a. a

Unted States Patent 01 fice Patented Nov. 9, 1971 U.S. Cl. 57145 28Clams ABSTRACT OF THE DISCLOSURE A lime gripping device having anumderlyimg set of preformed helical wires applied over the lime, and agripping member having helically formed wires grippimgly engaging thisunderlying set of wires. The gripping member is provided with means forengagimg an anchoring device.

This is a continuation of application Ser. No. 748,502, filed July 29,1968, and now abandoned.

This invention relates to mew different and unobvious lime emgagimgdevices, and methods of usimg such devices for dead endimg and pullinglimes.

Dead ends are used for gripping wires, cables, strands or other types oflines and find particular application in guying transmission towers,antenna towers, and other structures. The dead ends transfer the pull ofthe limes to the amchrimg structures at both ends of the line, and arealso often used to interconmect segment of a lime.

There have been several prior art proposals for dead ends suit-able forsuch gripping of limes. One common form of these dead ends in that whichutilizes helically formed resiliemt wires or wire elememts for grippinga line, which wires are bemt to form a bight for engaging theganchoringstructure. One example of this type of dead end is disclosed in US. Pat.No. 3,295,311 in the name et T. E. Butz et al. This device has beenextremely effective in dead end applications, especially in comjumctiomwith stranded metal wire limes such as guystramd, single elememts linesand relatively stiff fiber glass rods. However, with certain types oflimes such as fiber glass rope, which are sensitive to crushimg andlongitudinal displacement of the strands, these devices, while beingsuperior to other gripping devices, still had some tendenc to causecrushimg and longitudinal displacememt of the elememts especially underfield applied conditions where extreme care was not exercised inapplyimg the grip.

The sensitivity to crushing force is a characteristic of fiber glassrope, and also certain other types of rope formed of strands, each ofwhich strands are made up relatively thin elememts. This semsitivity ischaracterized by a propemsity toward weakemed areas on the rope causedby concentrated compression forces acting on the rope over a constrictedarea, damaging the elememts. This weakemed area is then likely to failbefore the rated breaking stremgth of the lime is reached.

Although the dead ends described in said Pat. No. 3,295,311 applieddirectly to the lime reduced the amount of this crushimg force ascompared to many devices pre Viously available, crushing damage stillwas oftem imduced to a large degree when the dead ends of the Butz etal. patent were mot carefully installed particularly under fieldconditions. Also, prior pulling devices, such as comealongs, tended toinduce crushing forces into the lime where the gripped the line to pullit.

Longitudinal displacement of the strands of a rope or similar strandedstructure is a condition wherein the strands are displacedlongitudinally with respect to each other. There may also be somelongitudinal displacement of the elememts withim givem strands. This maybe imduced by the gripping action of certain gripping devices, and isoften encountered when care is not exercised in applyimg a helicallyperformed dead end to a relatively flexible stranded structure. Althoughthis displacement may take place to a minimum degree in metal ropes andstrands, it is mormally mot of a sigmificamt nature. However, in fiberglass rope, this longitudinal displacement may be sufldent t0 permitsubstantial uneven or unequal longitudinal loading of the strands andelements comprising the line. When such unequal loading occurs, failureof the overloaded strands or elememts may occur resulting in overloadingthe remaiming strands or elememts which successively fail until ultimatefailure of the lime coeurs.

Also other gripping and pulling problems are encountered whem usimgprior art gripping and pulling devices on certain roped structures. Forexample, fiber glass rope is normally provided with a jacket of plasticor elastomeric material for protection. With prior art gripping devicesthis jacket had to be stripped in the region to be gripped beforeapplyimg the gripping device, simce application of gripping devices overthis jacket produces widely varying failure loads. This strippingoperation was time-consumimg and also the umderlying rope structurecould be damaged by this removal operation.

One of the most widely used prior art techniques of securing the end ofa fiber glass rope was potting or encapsulating. In a pottimg technique,the end portions of the fiber glass rope are first stripped of thejacketing material, and then encapsulated Withim a fitting by a resinwhich is allowed to cure inside of the fitting with the rope surroundedthereby, thus securing the fitting to the rope.

The emcapsulated, or potted fitting has been the conventional, orstandard prior art fitting for many types of limes imcluding fiber glassrope. In fact this is the type of fitting mormally applied to test thestremgth of the fiber glass rope. These potted fittimgs whilerepresemtimg the standard, have many serious limitations.

First, the fittimgs require a great deal of skill to apply properly,especially under field conditions. The line and the fittimgs must beproperly prepared and imgrediemts must be CarefuHy measured. Also theprocess of applyimg potted fittimgs is time comsuming, mot omly in theprep aration of the fittimgs and the lime and the mixing of theingrediemts, but also because of the time required for the encapsulatingmaterial to set. These drawbacks have restricted to some extemt the useof fiber glass rope.

Simce fiber glass rope has many attractive features for guying purposesfor many structures, such as antenma towers, it is especially desirablet0 overcome these prob lems t0 permit eflective use thereof for theseand other applications.

In accordance with the present invention, a line engagimg device isprovided which is comprised of an imner layer of helically performedelememts, applied to the lime, and a gripping member having helicallypreformed elememts wrappimgly engaging the inner layer with means forattachment of the gripping member to an amchorimg structure. Thisconfiguration mimimizes the crushing forces imduced into the line andalso mimimizes any longitudinal displacement of the strands or elementsof the strands. Also, this arrangement can be applied over the jacketingmaterial of the fiber glass limes.

This dual layer configuration of the gripping device also provides auseful device to grip limes for the pulling thereot, for applyimgtension thereto.

Still other advantages of the invention together with a fullerumderstanding thereof will become apparent from the followimgdescription t-aken in conjunction with the accompanying drawimgs inwhich:

FIG. 1 is a side elevatiomal view of a helically preformed elememt madefrom a wire;

FIG. 2 is a broken elevational view of several of the elements of FIG.1, formed into a sub-set;

FIG. 3 is a broken elevational view of several sub-sets of the elementsof FIG. 2, wrappingly engagimg a line to form a layering set;

FIG. 4 is an elevational view of a straight bight gripping member;

FIG. 5 is an elevational view of the member of FIG. 4, being wrappinglyengaged onto a line over the layering set of elements;

FIG. 6 is a completed assembly of the gripping member applied over thelayering set of elements;

FIG. 7 is an elevational view of the device of this invention being usedas a line emgaging element for applyimg tension to a line; and

FIG. 8 is an elevational view of still another embodi ment of a grippingmember applied over a layering set of elements on a line.

Referrimg now to the drawings, and for the present t0 FIG. 1, anindividual resilient helically preformed wire element .10, is shown.This element 10 may be formed in several ways. However, preferably thisforming is done as described in US. Pat. No. 2,588,663, issued to E. H.Schane. The helically bent wire is then severed into heli callypreformed elements -10 of the desired lengths. The elements may bestress relieved and the ends may be chamfered t0 eliminate sharp edges.

The element 10, thus formed is an open helix of hard drawn wire, suchthat it may be applied to a line from its side without permanentdeformation of the helix.

A plurality of the elements 10, as shown in FIG. 1, are assembled intosub-sets as shown in FIG. 2, and these sub-sets can then be applieddirectly to a line L as shown in FIG. 3. If desired the elements in thesubsets can have grit applied thereto to enhance the holding power as iswell known in the art. As illustrated herein, three sub-sets of fourelements each are applied to the line L. It is to be understood,however, that the number of elements in a sub-set as well as the numberof sub-sets can also vary widely, as will be described presently. In theillustrated embodiment, the line takes the form of a fiber glass rope orcable. This particular material was selected for illustration inasmuchas the gripping devices of this invention are particularly useful withfiber glass rope or cable; however, it is to be understood that thedevice can be used effectively with amy type of wery flexible line. (Asit is used herein the term line can include for example, a single wireor filament, a strand made up of a plurality of single wires, a cable orrope made from a plurality of strands, or wire made of a plurality oflongitudinally extending elements. It applies to conductors ofelectricity as well as limes employed for guying purposes.)

Fiber glass rope is often supplied with a jacket formed of a plastic orelastomeric material such as urethane. Such a jacket is shown on therope of FIG. 3, and designated with the reference character J. When sucha jacket is supplied it is considered as part of the rope. As can beseen in FIG. 3, the layering elements 10 are applied over this jacket I.Hence, when such a jacket is supplied on the rope there is no necessityto remove the jacket, as with prier art gripping devices. (The reasonwhy this device works eifectively over the jacket is not completelyunderstood, and in fact constitutes an unexpected benefit; however,certain theories of this and other improved results will be discussedpresemtly.)

It is preferable that the elements 10 be formed to the opposite hand oflay from the lay of the line; i.e., if the line is right hand of lay theelements 10 will be left hand of lay and vice versa. However, it iscontemplated that in some instances the rods 10 may be of the same handof lay as the lime and give satisfactory performance. Also, preferablythe mumber of elements in a sub-set and the number of sub-sets isselected such that when they are applied they will cover at least fiftypercent of the surface of the line, over which they extend, but have atotal spacing between the elements, the extent of which would besufficient for the introduction of at least one additional element ofthe same size. It is desirable that these elements cover at least fiftypercent of the surface to provide a firm holding base for the gflppimgmember to be applied later, but that they do not cover the surface s0completely that an additional element could not be applied. Thisprovides a spacing which allows for easy installation of the elements10, and also prevents bridging, thus permitting each of the elements 10to securely bear against the umderlyimg lime. Preferably the elements 10of the sub-sets are relatively small cross section and are comprised ofa relatively large number of wires. This is so that the elements can beapplied easily and will mot exert excessive pressure on the line. Also,this will provide a certain amount of desirable flexibility to the ropealthough it will stiien the line suficiently for the case of applicadonof the gripping device thereover. Additionally, a large number of smallelements provide greater contact area with the umderlyimg jacket, than afewer number of larger size elements covering the same area.

The applied sub-sets of helically preformed elements 10, provide anumderlyimg or layering set of elements over which a gripping member ordevice can be applied. The gripping device can take one of many formsincorporating preformed helical elements for grippingly emgaging the setof layering elements. One desirable and preferred form is shown in FIG.4, and designated by the reference character 12. As shown the grippingdevice 12 is comprised of a plurality of hard drawn wire elements l4,havimg helically preformed end portions 16, and an intermediatesubstantially straight portion 18, joining the helically preformed end;portions. The preformed portions 16, of each of the elements l4,substantially conform to each other as to pitch, length and internaldiameter, The elements 14 are positioned in side-by-side relationshipwith one another to form a group, and the group of elements is bentwithin the intermediate straight portion to form a bight section 18,which is free of a complete revolution. The opposite end portions 16, ofthe elements 14, extend from the straight bight section 18 and form apair of legs 16. This type of device is a conventional gripping devicewhich, along with its method of manufacture, is described in said Pat.3,295,311. The gripping device shown in FIG. 4 is then wrapped over thelayering set of elements 10, as shown in FIG. 5, With the legs 16 beingintertwisted With each other, until they have been completely applied asshown in FIG. 6. Preferably, as described in said Pat. 3,295,311, thelegs of the gripping device when intertwisted with each other form morethan a half lay, but less than full lay coverage of the layering set ofelements 10. (It is to be understood that the gripping members areapplied over a set of elements which themselves do not cover of thesurface of the line, there being a space as described above; hence, whenthe definitions of half lay and full lay coverage of the legs 16contained in said Pat. 3,295,311 include percent coverage of the legs,the percent must be based on 100% theoretical peripheral coverage of theline by the elements 10, i.e., as if there were sufiicient elements 10applied to the lime to provide 100% coverage of the underlying line.)

As can be seen in FIGS. 5 and 6, the hand of lay of the legs 16 of thegrippimg device 12 is opposite to that of the elements 10, and the sameas that of the line L. This opposite hand of lay is preferable, but itis contemplated that in some instances the legs 16' may be of the samehand of lay as the umderlyimg elements 10 and still give satisfactoryperformance. Because of this opposite hand of lay of the layeringelements and the legs of the gripping device, and also because of therigidity which the layering elements 10 provide, the relatively largediameter of wires of the gripping device can be relatively easilyapplied without encountering the difficulty that is encountered whentryimg to apply such large diameter of wires directly to a flexiblebody, such as the underlying fiber glass rope and particularly whentrying to apply the legs With the same hand of lay.

Also, as can be seen in FIG. 6, the underlying or layering set ofelements 10 preferably extends past the end of the legs 16 of thegrippimg device 12. This configuratien assures that the entire length ofthe grippimg device 12 will be in effective engagement with theumderlying structure. This extra length also provides for a steppedtransition of flexibility; i.e., the line itself beyond the underlyingset of elements is extremely flexible, while the line between the end ofthe layerimg elements and the end of the legs 16, is made somewhat lessflexible by the layerimg elements 10, and the line covered by both thelayerimg set of elements and the grippimg elements is quite stifi'.

As can be seen in FIGS. and 6, the bight 18' of the grippimg device 12is disposed to engage an anchoring structure A, and thus form a deadend.

Tests performed demonstrated that fiber glass ropes dead ended accordingto this invention as shown in FIG. 6, consistently developed greaterload carrying capacities than were developed With limes dead endedaccording to comvemtiomal prior art encapsulating or potting techniques.To test the strength of the dead end, the fittimgs (either the dead endfitting according to this invention or the potted fittimg according toprior teaching), are applied to opposite ends of the rope and gripped ina tensile testing device. Tension is applied until failure occurs. Ascan be seen from the table below, the fiber glass rope dead endedaccording to this invention consistently carried a higher load thanfiber glass rope dead ended by conventional potting techniques.

TABLE.TENSILE TEST ON INCH FIBER GLASS ROPE MANUFACTURED BY PACKARDELECTRIC DIVISION OF GENERAL MOTORS SOLD UNDER THE TRADEMARK GLASTRANRope breaking strength- Fitting pounds Test No.:

1 Potted fitting 1 .-do

Average et tests, 1, 2 and 3 Average of tests, 4, 5 and 6 1 Standardencapsulating technique employedmetal socket fitting for each end wasdegreased and acid treated, the jacket at each end of the strand wasremoved and the strands unwound; the unwound strands were degreased andthen inserted into the fittings; epoxy resin and hardener poured intothe socket and allowed to cure.

2 A layerimg set of helically preformed rods of the type shown in FIG.1, was applied to each end of the strand over the jacket; the wires wereof opposite hand of lay rom the strand. A grippimg member as shown inFIG. 4, was applied over the layerimg elements at each end, the hand o!lay of the legs was opposite to that oi the layerimg elements and thesame as the stramd.

As can be seen from the table above, in each instance line grippimgdevices formed according to this invention produced superior results tothe standard prior art encapsulated devices and techniques. Further,fittings according to the invention not only develop a higher loadcarrying capacity, they can be simply and rapidly applied undervirtually all field conditions.

Not only does the grippimg device formed according to this inventionprovide a superior device for securimg limes to an anchoring structure,it also provides a superior device for grippimg a lime to apply tensionthereto during the installation of the line.

FIG. 7 shows somewhat diagrammatically grippimg devices according tothis invention, used both to apply tension t0 a line and to secure thelime to an anchoring structure. First, ome end of the line is secured toan anchorimg point (mot shown) usually on the tower or pole. Then thepoint on the lime at which it is to be gripped to apply tension isselected, at which point a first set of layerimg elements 110, isapplied over which a first grippimg device 112, is applied. Theapplication of the layerimg elements and the grippimg device 112, isaccomplished as described above. A tension applyng device in the form ofa comeal0ng 2.0, is provided which has a hook 22, at one end, disposedto engage an eye 24, formed in the anchoring structure to which theother end of the lime is to be connected. The other end of the comealongis provided with a hook 26, attached to a ratcheting device 28, which inturn is connected to the hook 22 by a chain 30.

The ratchetimg device 28, is operable by a handle 32, which will movethe ratcheting device 28, along the chain 30.

In order to apply the desired tension to the line, the hook 22, isengaged with the eye 24, and the hook 26, is engaged With the bight 118of the grippimg device 112. The handle 32 is then operated to move theratcheting device on the chain 30 which will tighten the line. When thedesired tension has been applied to the line, the lime is out to thedesired length. The end of the line is then dead ended. This dead endingpreferably is done with layerimg and grippimg elements according to thisinventien. A second set of layerimg elements 210 is applied, in a manneras described previously, over which a grip ping device 212, is appliedalso in a manner as previously described, engaging the anchoringstructure A. The tension can be relieved from the temsioning device 20,transferring the load to the grippimg device 212. The first grippimgdevice 112 and the layerimg elements 110 can then be removed. Theseelements of course may be reused for additiomal temsioning operatioms ifthey are mot severely damaged.

One of the outstandimg advantages of using the mechamism of thisinvention for a device to apply tension, is that it does not cause anycrushing damage to the underlying strand, such as is often the case withcomvemtiomal prior art grippimg jaws of tensioming devices. Tests wereperformed to show the effect of using comvemtiomal prior art grippimgjaws to apply tension to a line as compared to the device of thisinvention. These tests were performed successively on test specimens ofA inch Glastran fiber glass ropes. For each test ome end of the specimenWas first dead ended With similar layerimg elements and a straight bightgrippimg device according to this invention as shown in FIG. 6. Next thespecimem was wrapped with a set of layerimg elements 110 near theopposite end thereof at the place where it was to 'be gripped fortension to be applied. The same size and type of elements were used foreach specimen. On ome specimen, a grippimg device 112, according to thisinvention was applied over the elements 110, in the manner as shown inFIG. 7 and engaged With the tensioning device 20. On the other specimena comvemtiomal grippimg jaw comealong was applied over the set ofelements 110 and engaged with a temsioning device 20. In each test theline was tensioned to about 5,000 pounds by the tensioning device.

In each test the other end of the specimen was dead ended with similarsets of layerimg elements and a grippimg device, according to thisinvention. The tension was released and the grippimg device, thetemsioning device, and the layerimg elements underlying were removed.

The specimens were each tensle tested by applying force thereon throughthe grippimg devices at opposite ends. The specimen which had beengripped by a grippimg device according to this invention, did not breakuntil it had exceeded its full rated breakage strength, in fact,breaking above 19,000 pounds with failure occurring at a location awayfrom where it had'been gripped by the grippimg device for tensioning. Onthe other hand, the specimen that had been gripped with the comvemtiomalgrippimg jaw type device failed at about 5,000 pounds, failure occurringat the place the where the jaws had gripped the specimen. These testsdemonstrated that aven covering the line by a set of layerimg elementswould not prevemt damage to the line by the jaws of conventionalgripping devices to such an extent that it was materially weakemed andhence failed well below its rated breaking strength.

The gripping devices of this invention and method of using them inapplying tension to a lime have been described in conjunction with usingsimilar gripping devices for a dead end; however, it is to be understoodthat the gripping devices and their use in applying tension are notlimited to situations where similar type of devices are used to dead endlimes, and they can be used in conjunction with other dead ends or deademding devices and techniques.

Referring now to FIG. 8, another form of a gripping device applied overthe underlying sets of wires 10 is shown. In this embodiment thegripping device includes a plurality of helically preformed wires 34,which are secured together at one end portion thereof, by a socketingdevice 36. The helically preformed wires 34 are formed t a common pitchlength and internal diameter to engage over the layering set of wires10. The socket device includes attachment means, in the form of a clevispin 38, which is adapted to engage an anchoring structure. The helicallypreformed wires 34, can be secured in the socketing device by any ofseveral conventional means. For exainple, the wires may be held in thesocket by a swaging or wedging action as shown in application Ser. No.729,610, filed May 16, 1968, now Pat. No. 3,575,519 entitled GrippingDevice, or they may be held in the device by encapsulating material asdisclosed in application Ser. No. 729,618, filed May 16, 1968, entitledDead -Ending Device, or application Ser. No. 729,619, filed May 16,1968, now Pat. No. 3,551,959, entitled Detachable Socketed Dead End.These of course are just illustrations of types of socketing devices andnot intended as limiting.

The illustration of both the socket type gripping devices, and the typewhere preformed wires are bemt to form a bight, are intended to bemerely illustrative of the many configurations of gripping devicesutilizing preformed helical elememts which may be used. These forms areespecially desirable for fiber glass rope application since theyminimize torsional stress induced to the line and fiber glass isespecially torque sensitive. However, it will be readily apparent tothose skilled in the art that there are many other configurations whichwill function as gripping devices for engaging over the layeringelememts 10, the illustrated embodiments merely representing preferredstructures which perform quite satisfactorily.

The exact reason for the excellent performance of the devices of thisinvention over other devices, particularly over helically formed devicesapplied directly to a line, is not completely understood. However, it isbelieved that there are several contributing factors which when takentogether produce the outstandimg performance. First, rope made of aplurality of strands which in turn are made up of a plurality ofelements is an extremely flexible structure. When it is attempted toplace relatively stiff helically preformed wires on this flexiblestructure, dificulty is encountered in that the rope tends to flexexcessively when the wires are being applied, which makes theinstallation diflicult. If under these circumstances, the grip is notcarefully applied the operation tends to produce longitudinaldisplacement of the strands and elememts With respect to each other,which as described above, can contribute to premature failure of thestructure, particularly in the case of fiber glass rope.

Also, when helically preformed wires which are to carry the pull aredirectly applied to rope structure, it is necessary that the wires havethe sarne hand of lay as the rope structure. If they are opposite handof lay and tension is applied, the result is that the gripping devicetends to unravel the rope under tension which contributes t0 ropefailure. Hence, it is necessary Whem applying gripping devices directlyto stranded structures that the helically pref0rmed wires have the sarnehand of lay as the rope. This increases the difliculty of applicationand increases the chance of longitudinal displacement of the strands orelememts if care is not exercised in applying the device.

Further, when wires of the sarne hand of lay are used there is minimumnumber of pressure points where the wires are bearing agaimst the rope,which tends to increase the concentration of the forces rather thandisperse them, contributing to or increasing the possibility of crushingdamage.

The dual layers structure of the present invention overcomes thesedisadvantages.

First, the underlying set of wires can be formed of thinner, less rigidmembers which can be more easily applied to the flexible rope structure.This is possible since the gripping action is not generated by thesewires, and hence, the great strength required to provide the grippingaction is not required.

Also, the underlying wires 10, can be of the opposite hand of lay of therope, which makes application to the rope much easier. This provides amuch improved structure for distribution of forces since wires havingthe opposite lay have a greater number of contact points with a greatnumber of strands, thus, increasing the force distribution. The heavierwires of the gripping device can then be applied over the underlying setof wires 10. This underlying set of wires 10, will greatly reduce theexternal flexibility of the wires to the desired amount, increasing thecase of application of the gripping device, thereto.

Also, the wires of the overlying gripping device 12, will be theopposite hand of lay of the underlying wires 10, and the sarne hand oflay as the lime L. This then allows the gripping device to be moreeasily applied to the underlying set of wires 10 and still retain thesame hand of lay as the underlying rope structure, so that detrimentalumwinding does not occur under tension.

This structure of opposite hand of lay of underlying wires and rope onone hand and underlying wires and overlyimg gripping device on the otherprovides an extremely desirable configuration for preventingconcentration of gripping forces in any one area widely distributingthese forces so that they do not contribute or cause a crushing actionof the underlying structure. It also provides a configuration which isrelatively easily applied to the structure which will not tend to causelongitudinal displacement of the strands and elememts making up theunderlying structure, and which will alford au extremely effectivedevice for transferring load from the underlying rope structure up tothe full potential of the rope itself.

While several embodiments of this invention have been shown anddescribed various adaptations and modifications can be made withoutdepartimg from the scope of the invention.

What is claimed is:

1. A device for gripping an elongated body comprising, a first set ofhelically preformed resilient elememts formed to a common pitch lengthand internal diameter, said elements of the first set being of a sizeand adapted to be applied to wrappingly engage a body without permanentdeformation of the elememts; a second set of resilient elememts, theelements of said second set having at least one end portion helicallyformed to a common pitch length and internal diameter and disposed forwrappingly engaging said first set of elememts in overlying relationshipwhen said first set is applied to the elongated body, means connected tosaid helically formed portions of said second set of elememts forengagement with an anchoring structure.

2. The invention as defined in claim 1, wherein the first set ofelememts is configured and arranged such that when they are applied to aline there will be unfilled space between the elements suflicient toaccommodate at least one additional element of the same size.

3. The invention as defined in daim 2, wherein the configuration of thefirst set of elements provides at least 50 percent coverage of theunderlying line of the portion of the line that will be covered thereby.

4. The invention as defined in claim 1, wherein the helically formed endportions of said second set of elements provide, upon intertwisting onthe first set of dements, a less than whole lay gripping portion butmore than half lay.

5. The invention as defined in daim 1 wherein the elements of said firstset and the helically formed portions of said second set of elements areof opposite hand of lay.

6. The invention as defined in claim 1, wherein said first set ofelements is longer than the helically formed portions of said second setof elements.

7. The invention as defined in daim 1, wherein the elements of saidfirst set are substantially less rigid than the elements of said secondset.

8. The invention as defined in daim 7, wherein the elements of saidfirst set are of smaller diameter than the elements of said second set.

9. The invention as defined in claim 1, wherein said second set ofelements are in side-by-side relationship defining a pair of helicallyformed leg portions connected 'by a bight portion.

10. The invention as defined in daim 9, wherein said bight portion isfree of a complete helical revolution.

11. The invention as defined in claim 1, wherein the elements of saidsecond set are secured by a socket member.

12. The combination comprising, a line, a gripping device thereforeincluding a set of resilient layering elements and a set of resilientgripping elements, each of said layering elements being of similar sizeand helically preformed to a common pitch and internal diameter andwrappingly engaging said line, the elements of said gripping set havingat least one end portion helically formed to a common pitch and internaldiameter, said helically formed end portions of said gripping elementsWrappingly engaging said layering elements in gripping relationshiptherewith, and means connected to said helically formed end portions ofsaid gripping elements engaging an anchoring structure.

13. The invention as defined in daim l2, wherein the elements of saidlayering set are arranged such that there will be unfilled space betweenthe elements suflicient to accommodate at least one additional dement ofthe same size.

14. The invention as defined in daim 13, wherein the layering set ofelements provided at least 50 percent coverage of the underlying line ofthe portion of the line covered thereby.

15. The invention as defined in daim 12, wherein the helically preformedend portions of said set of gripping elements provide, nponintertwisting on the first set of elements, a less than whole laygripping portion, but more than half lay.

16. The invention as defined in daim 12, wherein the elements of saidset of layering elements and the helically preformed end portions of thegripping elements are of opposite hand cf lay.

17. The invention as defined in daim l6, wherein the line is a strandedstructure and of opposite hand of lay as the set of1ayering elements.

18. The invention as defined in claim 12, wherein said set of layeringelements is longer than the intertwisted end portions of said set ofgripping elements.

19. The invention as defined in daim 12, wherein the elements of saidlayering set are substantially less rigid than the elements of saidgripping set.

20. The invention as defined in daim l9, wherein the elements of saidlayering set are of smaller diameter than the elements of said grippingset.

21. The invention as defined in daim 12, wherein the elements of saidgripping set are in side-by-side relationship providing a pair ofhelically formed leg portions connected by a bight portion.

22. The invention as defined in daim 2l, wherein said bight portion isfree of a complete helical revolution.

23. The invention as defined in daim 12, wherein elements of saidgripping set are secured by a socket member.

24. A method of tensioning a line to a predetermined amount comprisingthe steps of: providing a set of layering elements, said layeringelements being helically formed to a common pitch length and internaldiameter and configured for wrappingly engaging the line to betensioned, providing a gripping member including a plurality of elementshaving end portions helically formed t0 a common pitch length andinternal diameter and configured for wrappingly engaging said layeringelements, and engagement means connected to said helically formed endportions of said elements of the gripping member for engagement with astructure, wrappingly engaging said set of layering elements on saidline at a selected location; wrappingly engaging the helically formedend portions of the elements of said gripping device around saidlayering elements, engaging an anchoring structure and the engagementmeans of said gripping device With a tension applying device, andapplying the desired tension to said line.

25. The method as defined in daim 24, wherein said line is connected toan anchoring structure after the desired tension has been applied.

26. The method as defined in daim 25, wherein said line is connected tosaid anchoring structure by the steps of providing a second set oflayering elements, wrappingly engaging said second set With said line,providing a second gripping member, wrappingly engaging said secondgripping member With said layering elements and engaging said engagementmeans With said anchoring structure.

27. A device for gripping an elongated body comprising, a set ofhelically preformed resilient elements formed t0 a common pitch lengthand internal diameter, said elements of the set being of a size andadapted to be applied to wrappingly engage a body without permanentdeformation of the elements; and gripping means disposed to grippinglyengage said set of helically preformed elements when said set is appliedto the body, said gripping means including means to engage an anchoringstructure to secure the line thereto.

28. The combination comprising, a line, a gripping device thereforeincluding a set of resilent layering elements, each of said layeringelements =being of similar size and helically preformed to a commonpitch and internal diameter and wrappingly engaging said line, andgripping means grippingly engaging said layering elements, said grippingmeans inclnding means engaging an anchoring structure and securing theline thereto.

References Cited UNITED STATES PATENTS 3,089,567 5/1963 Sullivan 57-145UX 3,190,065 6/1965 Little 57-145 3,267,658 8/1966 Schlein 57-1453,295,311 1/1967 Butz et al. 57-145 3,299,626 1/1967 Payer et al. 57-1453,315,457 4/1967 Stirn 57-145 3,336,744 8/1967 Peene 57-145 3,355,54211/1967 Finn 174-79 3,406,513 10/1968 Butz et al. 57-145 DONALD E.WATKINS, Primary Examiner U.S. Cl. X.R. 174-79; 248-63

